eclass/ltprune.eclass

   1 # Copyright 1999-2017 Gentoo Foundation
   2 # Distributed under the terms of the GNU General Public License v2
   3
   4 # @ECLASS: ltprune.eclass
   5 # @MAINTAINER:
   6 # Michał Górny <mgorny@gentoo.org>
   7 # @BLURB: Smart .la file pruning
   8 # @DESCRIPTION:
   9 # A function to locate and remove unnecessary .la files.
  10 #
  11 # Discouraged. Whenever possible, please use much simpler:
  12 # @CODE
  13 # find "${D}" -name '*.la' -delete || die
  14 # @CODE
  15
  16 if [[ -z ${_LTPRUNE_ECLASS} ]]; then
  17
  18 inherit toolchain-funcs
  19
  20 # @FUNCTION: prune_libtool_files
  21 # @USAGE: [--all|--modules]
  22 # @DESCRIPTION:
  23 # Locate unnecessary libtool files (.la) and libtool static archives
  24 # (.a) and remove them from installation image.
  25 #
  26 # By default, .la files are removed whenever the static linkage can
  27 # either be performed using pkg-config or doesn't introduce additional
  28 # flags.
  29 #
  30 # If '--modules' argument is passed, .la files for modules (plugins) are
  31 # removed as well. This is usually useful when the package installs
  32 # plugins and the plugin loader does not use .la files.
  33 #
  34 # If '--all' argument is passed, all .la files are removed without
  35 # performing any heuristic on them. You shouldn't ever use that,
  36 # and instead report a bug in the algorithm instead.
  37 #
  38 # The .a files are only removed whenever corresponding .la files state
  39 # that they should not be linked to, i.e. whenever these files
  40 # correspond to plugins.
  41 #
  42 # Note: if your package installs both static libraries and .pc files
  43 # which use variable substitution for -l flags, you need to add
  44 # pkg-config to your DEPEND.
  45 prune_libtool_files() {
  46         debug-print-function ${FUNCNAME} "$@"
  47
  48         local removing_all removing_modules opt
  49         for opt; do
  50                 case "${opt}" in
  51                         --all)
  52                                 removing_all=1
  53                                 removing_modules=1
  54                                 ;;
  55                         --modules)
  56                                 removing_modules=1
  57                                 ;;
  58                         *)
  59                                 die "Invalid argument to ${FUNCNAME}(): ${opt}"
  60                 esac
  61         done
  62
  63         local f
  64         local queue=()
  65         while IFS= read -r -d '' f; do # for all .la files
  66                 local archivefile=${f/%.la/.a}
  67
  68                 # The following check is done by libtool itself.
  69                 # It helps us avoid removing random files which match '*.la',
  70                 # see bug #468380.
  71                 if ! sed -n -e '/^# Generated by .*libtool/q0;4q1' "${f}"; then
  72                         continue
  73                 fi
  74
  75                 [[ ${f} != ${archivefile} ]] || die 'regex sanity check failed'
  76                 local reason= pkgconfig_scanned=
  77                 local snotlink=$(sed -n -e 's:^shouldnotlink=::p' "${f}")
  78
  79                 if [[ ${snotlink} == yes ]]; then
  80
  81                         # Remove static libs we're not supposed to link against.
  82                         if [[ -f ${archivefile} ]]; then
  83                                 einfo "Removing unnecessary ${archivefile#${D%/}} (static plugin)"
  84                                 queue+=( "${archivefile}" )
  85                         fi
  86
  87                         # The .la file may be used by a module loader, so avoid removing it
  88                         # unless explicitly requested.
  89                         if [[ ${removing_modules} ]]; then
  90                                 reason='module'
  91                         fi
  92
  93                 else
  94
  95                         # Remove .la files when:
  96                         # - user explicitly wants us to remove all .la files,
  97                         # - respective static archive doesn't exist,
  98                         # - they are covered by a .pc file already,
  99                         # - they don't provide any new information (no libs & no flags).
 100
 101                         if [[ ${removing_all} ]]; then
 102                                 reason='requested'
 103                         elif [[ ! -f ${archivefile} ]]; then
 104                                 reason='no static archive'
 105                         elif [[ ! $(sed -nre \
 106                                         "s/^(dependency_libs|inherited_linker_flags)='(.*)'$/\2/p" \
 107                                         "${f}") ]]; then
 108                                 reason='no libs & flags'
 109                         else
 110                                 if [[ ! ${pkgconfig_scanned} ]]; then
 111                                         # Create a list of all .pc-covered libs.
 112                                         local pc_libs=()
 113                                         if [[ ! ${removing_all} ]]; then
 114                                                 local pc
 115                                                 local tf=${T}/prune-lt-files.pc
 116                                                 local pkgconf=$(tc-getPKG_CONFIG)
 117
 118                                                 while IFS= read -r -d '' pc; do # for all .pc files
 119                                                         local arg libs
 120
 121                                                         # Use pkg-config if available (and works),
 122                                                         # fallback to sed.
 123                                                         if ${pkgconf} --exists "${pc}" &>/dev/null; then
 124                                                                 sed -e '/^Requires:/d' "${pc}" > "${tf}"
 125                                                                 libs=$(${pkgconf} --libs "${tf}")
 126                                                         else
 127                                                                 libs=$(sed -ne 's/^Libs://p' "${pc}")
 128                                                         fi
 129
 130                                                         for arg in ${libs}; do
 131                                                                 if [[ ${arg} == -l* ]]; then
 132                                                                         if [[ ${arg} == '*$*' ]]; then
 133                                                                                 eerror "${FUNCNAME}: variable substitution likely failed in ${pc}"
 134                                                                                 eerror "(arg: ${arg})"
 135                                                                                 eerror "Most likely, you need to add virtual/pkgconfig to DEPEND."
 136                                                                                 die "${FUNCNAME}: unsubstituted variable found in .pc"
 137                                                                         fi
 138
 139                                                                         pc_libs+=( lib${arg#-l}.la )
 140                                                                 fi
 141                                                         done
 142                                                 done < <(find "${D}" -type f -name '*.pc' -print0)
 143
 144                                                 rm -f "${tf}"
 145                                         fi
 146
 147                                         pkgconfig_scanned=1
 148                                 fi # pkgconfig_scanned
 149
 150                                 has "${f##*/}" "${pc_libs[@]}" && reason='covered by .pc'
 151                         fi # removal due to .pc
 152
 153                 fi # shouldnotlink==no
 154
 155                 if [[ ${reason} ]]; then
 156                         einfo "Removing unnecessary ${f#${D%/}} (${reason})"
 157                         queue+=( "${f}" )
 158                 fi
 159         done < <(find "${D}" -xtype f -name '*.la' -print0)
 160
 161         if [[ ${queue[@]} ]]; then
 162                 rm -f "${queue[@]}"
 163         fi
 164 }
 165
 166 _LTPRUNE_ECLASS=1
 167 fi #_LTPRUNE_ECLASS